Plate clamping mechanism for printing machines



' Aug. 11, 1936.- F. LAMATSCH v 2,050,851 PLATE CLAMPING MECHANISM FORPRINTING MACHINES Filed May 25, 1954 I Patented Aug. 11, 1936 UNETESTATES zpsassi I FA'E'ENT OFFIE PLATE CLAMPING MECHANISM FOR PRINTINGMACHINES Application May 25, 1934, Serial No. 727,390

9 Claims.

This invention relates to plate clamping mechanism for rotary printingpresses, having for its object the provision of certain desiredimprovements in mechanism of the character indicated with a view to amore convenient and efficient operation thereof.

A special object of the invention is to provide a plate lockup of adesign and construction particularly adapted to permit a more facilemanipulation of a plate clip while permitting the attainment of a narrowmargin or space between adjacent pages on the printed sheet.

Another object of the invention is the provision of a plate clamping orlockup mechanism having a novel plate clip operating device particularlydesigned and contrived to move axially with the said clip in such manneras to permit free access to the device between adjacent and/oroppositely positioned plates on a form cylinder, so that the operatormay actuate the device without the hindrance and inconvenience hithertopresented i from the adjacent and overhanging bevelled edge of theadjoining plate.

It is also an object of the invention to provide a plate lockuparrangement of generally improved construction, whereby the device willbe simple, durable and inexpensive in construction, as well asconvenient, practical, serviceable and efficient in its use.

30 With the foregoing and other objects in view, which will appear asthe description proceeds, the invention resides in the combination andarrangement of parts, and in the details of con- I struction hereinafterdescribed and claimed.

35 The preferred embodiment of the invention is illustrated in theaccompanying drawing, where- Figure 1 is a top plan view of theinvention as applied to a form cylinder, shown fragmentarily,

40 the plate clips being in operative, plate clamping position;

Figure 2 is an end elevational view, partly in section, as seen in thedirection of the arrow 2 of Figure 1; and

45 Figure 3 is a transverse view taken on the line and as seen in thedirection of the arrow 3 of Figure 1, the operating means for the plateclips being locked to prevent loosening of the clip from the printingplate.

50 In the several views of the preferred form of the invention, lldesignates generally a plate cylinder whereon is detachably mounted aplurality of half rings or semi-circular segments l I,

each provided with a longitudinally extending recess or opening l2wherein a plate clip 13 is slidably arranged. The clip i3 is formed withlaterally extending notches which receive inwardly directed projectionsor shoulders I i, I5 provided on the opposite walls of each groove, thesaid projections serving as ways to slidably support 5 the clips. Theupper surface of each clip I3 is undercut to provide a lip l6, which isadapted to operatively engage the bevelled edge of a printing plate.Each of the clips l3, in the form shown by way of example in Figure 1,which are 10 arranged adjacent the center of the cylinder and adapted tobe moved in opposite directions to engage and disengage their respectiveplates P, P, is provided with a threaded bore which receives a screwshaft I? having a squared portion 20 where- 15 on a manipulating toothedwheel I8 is slidably mounted, it being understood that other clipassemblies similar to that shown may be provided elsewhere on thecylinder in the customary positions for coaction with other printingplates (not 20 shown). The squared portion 20 of the shaft I! has areduced and rounded end or gudgeon l9 rotatably received in a tappedhole or pocket formed in a block or abutment 2| fastened in any suitablemanner as by screws 22 to the bottom of the 25 groove l2, the screws 22also serving to secure each half ring I l to the body portion of thecylinder II. The shaft I! is also provided with an annular shoulder 23which abuts against an adjacent portion of the block 2|, while the innerend of the said shaft is engaged against a Wall of the recess l2, sothat its longitudinal movement is prevented.

As an additional feature of the present invention, a resilient pawl ordog 25, detachably secured by screws 26 to the bottom of each clip I3,is provided, the said dog having an upwardly extending finger orprojection 21 adapted to retain the toothed wheel IS in juxtaposition tothe head of the clip l3, the dog 25 also serving to prevent rotation ofthe said wheel when the clip is clampingly engaged with a printing platein order to prevent accidental disengagement of the latter from thecylinder II.

The function and general manner of operation of the device, in largemeasure indicated above, may be summarized as follows:

Assuming a printing plate P or P has been placed on the cylinder in theusual manner, the clip adjacent thereto will be moved into clampingengagement with same by rotating the toothed wheel IS, the wheel beingpreferably actuated by a suitable operating tool (not shown) having forexample, a gear segment to engage the teeth of the wheel is. As theplate clip moves either into or out of engagement wtih the printingplate, the toothed wheel l8 will be maintained against translationalmovement and in the same position relatively to the said clip by thefinger 21 so that the operator may conveniently apply the operating toolor ratchet member to the wheel I8 as the latter and the clip l3 moveaxially along the screw shaft. By further inspection of Figure 3, itwill be understood that when a clip is dis- 10 engaged from its adjacentplate and further moved in an axial direction to the limit of the spaceprovided in the groove l2, the finger 21 will abut against the block 2|thereby preventing further movement of the wheel while still permittingthe application of the operating tool thereto.

Various sizes of printing plates, it will be understood, may beaccommodated on the cylinder I l by adjusting the clip l3 to the extentrequired. In conventional plate clamping apparatus where clip operatingmechanism is provided between adjacent plates, the said operatingmechanism is located constantly and inconveniently adjacent andpartially under the overhanging edge of the adjacent printing plate sothat manipulation of the mechanism is at all times made awkward andinconvenient. In the instant device, on the contrary and by reason ofthe fact that the manipulating means moves with the clip, the said ma- Lnipulating means or wheel l8 for the greater part of its axial movementand particularly when effective to operatively engage the clip with theprinting plate, is so located in the space between the edge of theadjacent printing plate and the clip H) as to permit an unimpededapplication of the operating tool to the wheel I 8. It will be notedthat only at those times when the operating wheel I8 is carried axiallyto the limit of its outer travel, will a portion of its rim be foundunder the edge of the adjacent printing plate and then only at a timewhen no working pressure is required. A partial. rotation of the wheelin this last mentioned position will move the rim of same into the openspace alluded to above. When the clip i3 is substantially in the plateclamping position indicated in full lines in Figure 3, the wheel I8 islocked by the pawl against rotation, thereby preventing accidentalrelease of the printing plate. When the shaft H is turned in a clockwisedirection by the wheel [8, the latter will be slid on the squaredportion 20 of the shaft in a direction from left to right by themovement of the clip in withdrawing from the adjacent printing plate,thesaid wheel in the completely released position of the plate beingthrust or slid on the shaft by the clip into a position where the fingerwill be juxtaposed against or abut against the block 2|.

As shown in Figure 1, it will be noted that a pair of plate clips of theform embodying the present invention, are provided at a position whichmay be adjacent to the center of the cylinder, but it will beunderstood, of course, that the mechanism described and illustratedlends itself equally to the incorporation of similar plate clips atother portions of the cylinder, and wherever an individual plateclamping mechanism is necessary and/or desirable. When desired, any ofthe half rings or segments ll containing the clip assemblies may beconveniently removed from the cylinder l l by unfastening the screws 22,after which any individual clip may be removed from its respectivesegment.

It will be understood that the invention may 75. be embodiedin otherspecific forms without departing from the spirit or essential attributesthereof, and it is therefore desired that the present embodiment beconsidered in all respects as illustrative and not restrictive,reference being had to the claims rather than to the foregoing 5description to indicate the scope of the invention.

1. In a device of the character described, the combination with acylinder having a recess and adapted to receive a printing plate, aplate en- 10 gaging clip arranged in said recess, said clip having athreaded bore, a screw shaft engaged in said bore and having anunthreaded portion, a toothed operating wheel slidably and non-rotatablymounted on the unthreaded portion, a pawl fas- 15 tened to the clip andengageable with the toothed wheel, and other means including an abutmentsecured to the cylinder for preventing axial movement of the shaftrelatively to the cylinder, said pawl serving to retain the operatingwheel against 20 translational movement relatively to the clip.

2. In a clamping mechanism for securing a printing plate to a formcylinder having a recess,

a plate clip vslidable in the recess, a member having a screw threadedportion thereon and an un- 25 threaded portion, said clip beingconnected to said threaded portion, an abutment removably secured in therecess, a gudgeon formed on the member and rotatably arranged in theabutment,

a manually operable member slidably movable on the unthreaded portion ofthe member, and. a device for locking the manually operablememberagainst rotation and for preventing axial movement of same relatively tothe clip.

3. In a device. of the character described, the

combination with a plate cylinder, of means removably secured to saidcylinder and having a recess, a plate engaging clip slidably mounted inthe recess, other means integrally formed in the first mentioned meansfor guiding the clip in the 40 recess, threaded means connected to-saidclip for moving same, a member moving with the clip for operating thethreaded means, and an abutment rotatably receiving the threaded meansat one end, said threaded means having its other end 4,5

der for retaining said clip slidably supported in 65:

the recess, a member rotatably engaged with said clip for moving same ina direction parallel with the axis of the cylinder, other means forpreventing longitudinal movement of the member relatively to thecylinder, manually operable 60 means slidably and non-rotatably mountedon the member for turning the same to move the clip into and out ofengagement with the plate, and a pawl secured to the clip, said pawlserving to prevent rotation of the manually operable means 65 andconsequently of the member when the clip is operatively engaged with aplate, and to restrain the said member against translational movementrelatively to the clip when the latter is moved.

5. In a device of the character described, the 7 the combination with aform cylinder having a recess and adapted to receive a printing plate,of a plate engaging clip slidably supported in the recess, meansthreadedly engaged in the clip for moving same in a direction parallelto the axis of the cylinder to engage and disengage a printing platearranged on the said cylinder, said means having a rectilinear portion,a toothed wheel slidably but non-rotatably mounted on the rectilinearportion, and a pawl detachably secured to the clip and operativelyengageable with the toothed wheel for locking same against rotation whenthe plate clip is clampingly engaged with the printing plate and forretaining the wheel against translational movement relatively to theclip.

6. In a clamping mechanism for securing a printing plate to a formcylinder having a recess, a plate clip slidable in ways formed in therecess, a member having a screw threaded portion thereon and anunthreaded portion, an abutment secured in the recess, said abutmentrotatably supporting the member at one end, a manually operable elementaxially movable on the unthreaded portionof the member, and meanssecured to the clip for retaining the element against translationalmovement relatively to the clip.

7. In a clamping mechanism for securing a printing plate to a formcylinder having a recess, a clamp member having a screw thread with anaxis parallel to the cylinder axis, a threaded element engaging the saidscrew thread and. rotatably supported in the recess and held againstaxial movement, and an operating member seheld in the recess againstaxial movement, and an operating wheel slidable axially on theunthreaded portion of the screw member but prevented from rotationalmovement with respect thereto; said operating wheel normally being heldagainst axial motion with respect to the clamp member.

9. In a mechanism of the character described for securing a printingplate to a form cylinder having a recess, a clamp member having a screwthread with an axis parallel to the cylinder axis, an operating membersecured to the clamp member but rotatable with respect thereto, and arotatably supported element in the recess having a threaded portionengaging the screw thread and a prism portion on which the operatingmember is slidably and non-rotatably fitted.

FREDERICK LAMATSCH.

